{"title":"Distributed (Space-Time) Codes for the MIMO Multihop Channel via Partitions of the Channel","authors":"Sheng Yang, J. Belfiore","doi":"10.1109/ITWITWN.2007.4318050","DOIUrl":"https://doi.org/10.1109/ITWITWN.2007.4318050","url":null,"abstract":"Summary form only given. In this paper, we consider multiantenna multihop relay channels in which the source signal arrives at the destination through N independent relaying hops in series. The main concern of this work is to design relaying strategies that efficiently utilize the relays in such a way that the diversity is maximized. First, we focus on the amplify-and-forward (AF) strategy with which the relays simply scale the received signal and retransmit it. More specifically, we characterize the diversity-multiplexing tradeoff (DMT) of the AF scheme in a general multihop channel with arbitrary number of antennas and arbitrary number of hops. The DMT is derived in closed-form expression as a function of the number of antennas at each node: as a first step, we provide some basic results on the DMT of the general Rayleigh product channels. It turns out that these results have very simple and intuitive interpretation. Then, the results are applied to the AF multihop channels which is shown to be equivalent to the Rayleigh product channel, in the DMT sense. Then, we mitigate the diversity suboptimality of the AF scheme via two kinds of partitions of the multihop channel : serial and parallel partitions. The serial partition corresponds to the intermediate decoding scheme. By supposing the relaying nodes could have full antenna cooperation, we study the fundamental problem that is when and where to decode to avoid diversity degradation. This scheme has minimum coding delay. The parallel partition corresponds to the distributed space-time processing. We establish conditions for the parallel partition to achieve the maximum diversity of the multihop channels. The parallel partition being rate-deficient in general, we propose a flip-and-forward (FF) scheme that achieves both the maximum diversity gain and multiplexing gain. The FF scheme is based on the parallel partition and works in a completely distributed manner. Coding schemes for both relaying strategies are proposed as well.","PeriodicalId":257392,"journal":{"name":"2007 IEEE Information Theory Workshop on Information Theory for Wireless Networks","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115545583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multidimensional Walsh Transform and a Characterization of Bent Functions","authors":"K. Nyberg, Miia Hermelin","doi":"10.1109/ITWITWN.2007.4318037","DOIUrl":"https://doi.org/10.1109/ITWITWN.2007.4318037","url":null,"abstract":"In this paper, a multidimensional Walsh transform is used to obtain a characterization of vector-valued bent function in terms of the value distributions of the translates of the function by linear functions.","PeriodicalId":257392,"journal":{"name":"2007 IEEE Information Theory Workshop on Information Theory for Wireless Networks","volume":"132 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115774411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Actions of the Unitary Group on Irreducible/Primitive Polynomials and Their Applications to Randomness of Sequences","authors":"S. Golomb, G. Gong","doi":"10.1109/ITWITWN.2007.4318055","DOIUrl":"https://doi.org/10.1109/ITWITWN.2007.4318055","url":null,"abstract":"This paper investigates how irreducibility and primitivity can be preserved when the unitary group acts on irreducible or primitive polynomials. Applying these operators to sequences and their discrete Fourier spectra, the weight preserving property is obtained. Some new randomness criteria are introduced in terms of these operators, which are suitable for measuring unpredictibility of pseudo-random sequences employed in stream ciphers.","PeriodicalId":257392,"journal":{"name":"2007 IEEE Information Theory Workshop on Information Theory for Wireless Networks","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131008435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Binary Linear Network Codes","authors":"Hsiao-feng Lu","doi":"10.1109/ITWITWN.2007.4318068","DOIUrl":"https://doi.org/10.1109/ITWITWN.2007.4318068","url":null,"abstract":"Network coding over a delay-free acyclic communication network with single source is considered in this paper. The network is modeled as a directed acyclic graph G where each edge in G is assumed to have unit link capacity. Previous works on network coding require a sufficiently large field such that the network has either a linear multicast, a linear broadcast, or a linear dispersion solution. For certain graphs, it is also known that linear network codes over a field of smaller size might not exist. In this paper, we propose a linear network code with memory and show that for any directed acyclic network with single source, there always exists a binary linear dispersion network code. Such code can be explicitly constructed and requires only the binary field for realization. Thus, this approach would dramatically reduce the hardware complexity for code implementation. Also contained in this paper is an explicit construction of binary linear broadcast network code for any directed acyclic networks.","PeriodicalId":257392,"journal":{"name":"2007 IEEE Information Theory Workshop on Information Theory for Wireless Networks","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125308257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jared Grubb, S. Vishwanath, Yingbin Liang, H. Poor
{"title":"Secrecy Capacity of Semi-deterministic Wire-tap Channels","authors":"Jared Grubb, S. Vishwanath, Yingbin Liang, H. Poor","doi":"10.1109/ITWITWN.2007.4318063","DOIUrl":"https://doi.org/10.1109/ITWITWN.2007.4318063","url":null,"abstract":"This paper studies secrecy capacity in a semi-deterministic setting, in which the channel between legitimate users (called Alice and Bob) is deterministic, while that between Alice and the eavesdropper (called Eve) is a discrete memoryless channel. Such a model is particularly relevant when a pre-existing error correcting code tailored to the legitimate channel is in use on top of which secret information is to be shared. First, a point-to-point setting is considered with a single wiretapper, a situation in which the secrecy capacity has an elegant characterization. Next, a generalized multiple access setting with confidential messages is considered in which each user wishes to communicate secret information to a common destination without the other determining its message. In this latter situation, outer bounds on the secrecy capacity are obtained.","PeriodicalId":257392,"journal":{"name":"2007 IEEE Information Theory Workshop on Information Theory for Wireless Networks","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124132686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Constructing Optimal Division Algebras for Space-Time Coding","authors":"R. Vehkalahti","doi":"10.1109/ITWITWN.2007.4318042","DOIUrl":"https://doi.org/10.1109/ITWITWN.2007.4318042","url":null,"abstract":"In [1] the authors suggested that in order to derive energy efficient space-time MIMO codes from orders of the division algebras one should use maximal orders instead of natural ones. They also described the division algebras that have the best maximal orders in terms of minimum determinant vs. average power. However, they were able to construct division algebras that were optimal only in few separate cases. In this paper we are addressing this problem and giving an explicit construction for optimal division algebras of arbitrary degree in the case when the center is Q(i). We note that all the results of this paper can be found from [2]. The goal of this paper is to give a simple representation of construction methods of [2].","PeriodicalId":257392,"journal":{"name":"2007 IEEE Information Theory Workshop on Information Theory for Wireless Networks","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129744972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Low Complexity Two Stage Detection Scheme for MIMO Systems","authors":"M. Chouayakh, A. Knopp, B. Lankl","doi":"10.1109/ITWITWN.2007.4318062","DOIUrl":"https://doi.org/10.1109/ITWITWN.2007.4318062","url":null,"abstract":"This paper provides an approach to reach a near maximum likelihood performance, for MIMO systems, with a strongly reduced computational effort. This method is based on a two-step detection. The first detection step will be performed by using a MMSE equalizer and a subsequent decision unit The second step is a reduced search (RS) algorithm, that is applied only in a neighborhood of the detected symbols of the first step. For complexity reasons only the least reliable symbols are processed by the RS algorithm. The simulation results show that this MMSE RS detector outperforms the MMSE V-BLAST detector. It provides an improved performance using the same complexity.","PeriodicalId":257392,"journal":{"name":"2007 IEEE Information Theory Workshop on Information Theory for Wireless Networks","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122495014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"SER Expressions for Double Differential Modulation","authors":"M. Bhatnagar, A. Hjørungnes","doi":"10.1109/ITWITWN.2007.4318064","DOIUrl":"https://doi.org/10.1109/ITWITWN.2007.4318064","url":null,"abstract":"We present symbol error rate (SER) expressions for the double differential (DD) modulation with MPSK constellations (DDMPSK) over AWGN, Rayleigh, and Ricean fading channels with carrier offsets in a single-input single-output (SISO) system. A closed-form expression is derived for SER in double differential binary phase shift keying (DDBPSK) over AWGN channels with carrier offset. Next, we derive a closed-form solution for the SER of DDBPSK and lower and upper bounds over the SER for DDMPSK signals over Rayleigh fading channels with carrier offset. A closed-form SER formulation for DDBPSK over Ricean fading channel with carrier offset is also presented.","PeriodicalId":257392,"journal":{"name":"2007 IEEE Information Theory Workshop on Information Theory for Wireless Networks","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124962299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Rank Distance Codes for ISI channels","authors":"S. Dusad, S. Diggavi, A. R. Calierbank","doi":"10.1109/ITWITWN.2007.4318026","DOIUrl":"https://doi.org/10.1109/ITWITWN.2007.4318026","url":null,"abstract":"Designs for transmit alphabet constrained space-time codes naturally lead to questions about the design of rank distance codes. Recently, diversity embedded multi-level space-time codes for flat fading channels have been designed by using sets of binary matrices with rank distance guarantees over the binary field and mapping them onto QAM and PSK constellations. In this paper we give the design of diversity embedded space-time codes for fading Inter-Symbol Interference (ISI) channels with provable rank distance guarantees. In the process of doing so we also get a (asymptotic) characterization of the rate-diversity trade-off for multiple antenna fading ISI channels when there is a fixed transmit alphabet constraint. The key idea is to construct and analyze properties of binary matrices with the particular structure induced by ISI channels.","PeriodicalId":257392,"journal":{"name":"2007 IEEE Information Theory Workshop on Information Theory for Wireless Networks","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129740847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Distributed Transmit Diversity in Relay Networks","authors":"C. Akçaba, Patrick Kuppinger, H. Bölcskei","doi":"10.1109/ITWITWN.2007.4318070","DOIUrl":"https://doi.org/10.1109/ITWITWN.2007.4318070","url":null,"abstract":"We analyze fading relay networks, where a single-antenna source-destination terminal pair communicates through a set of half-duplex single-antenna relays using a two-hop protocol with linear processing at the relay level. A family of relaying schemes is presented which achieves the entire optimal diversity-multiplexing (DM) tradeoff curve. As a byproduct of our analysis, it follows that delay diversity and phase-rolling at the relay level are optimal with respect to the entire DM-tradeoff curve, provided the delays and the modulation frequencies, respectively, are chosen appropriately.","PeriodicalId":257392,"journal":{"name":"2007 IEEE Information Theory Workshop on Information Theory for Wireless Networks","volume":"169 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121693582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}